Rebuilding Sherwood Raw Water Pump

[Miljack]

I guess I should ask if the r/w pump is leaking water from around the shaft area, is that a bad seal? Any other cause for the r/w pump to leak? Mine is mounted to the center of the crank pulley.

[TRBenj]

Mine is mounted to the center of the crank pulley.

Huh?

You dont have a PCM?

[Miljack]

Tim,
it's a PCM python engine, maybe they used a different setup on these because of the physical size of the engine package?

[Rock_Toy]

So, I finally got it done. Replaced everything internally, painted everything externally and slapped it back together. Let me tell you, this thing was a pain in the you know what!! Hopefully, all of my cooling problems will be behind me and I can have a good time on the boat this weekend.

BTW, can someone confirm for me that the water travels the long way around the pump? Here is what the impeller looked like prior to the rebuild. Does that look right?

[Rock_Toy]

Pics of the rebuilt pump:

[Rock_Toy]

Success!!! Before, the motor was running at 200+ degrees. Now I can't get it to go over 140. Would rather it were running cool than hot.

[sijiafin]

I would actually recommend that you just get a new water pump versus trying to repair it, I know firsthand how messy that can get! If you're interested I have a few ones lying around the house or you can find a really cool fluid pump right here.

[DanielC]

Yes, the water travels the long way around the pump. Think about it, the water gets squished out as the impeller blades are crushed in by cam in the pump housing, on the outlet side, and sucked back in from the lake as the blades open up on the other side of the cam. The big space in between the impeller blades carries the water around the pump.

[Toster]

Correct Way?

From reading DanialC's post I beleve this is the correct way. In this picture it is going right to left.

So, I finally got it done. Replaced everything internally, painted everything externally and slapped it back together. Let me tell you, this thing was a pain in the you know what!! Hopefully, all of my cooling problems will be behind me and I can have a good time on the boat this weekend.

BTW, can someone confirm for me that the water travels the long way around the pump? Here is what the impeller looked like prior to the rebuild. Does that look right?

[JayG80]

I just rebuilt the Sherwood Pump in my 650 hr 2002 Ski Nautique and it is fairly easy. My pump is a Sherwood G20 that has been superseded to G21 ($378) and that price is a bit steep compared to the replacement seat & seal kit. Discount Inboard Marine part no. 32911 is $24.50. The key to rebuilding is not removing the pulley from the shaft. Vince at DIM said he had a ruined pump on the shelf from trying to remove the pulley. He said - "remove the snap ring - not the pulley."

A pair of snap ring pliers is handy. Numbers provided below are from Sherwood Assembly Instructions http://www.sherwoodpumps.com/FileAtt...09959_TECH.pdf

Remove the two bolts that mount the pump to the engine and then remove the v-belt. (1/2" wrench if recall correctly)
Use a silver sharpie or nail polish and make an alignment mark on the body and housing so you can assemble back in correct configuration.
Remove the 3 bolts that hold the body (3) to the housing (4) and let water drain into bilge. (7/16" wrench IIRC)
I left the 4 month old impeller (5) in place and replaced the spacer plate (7) with the 3 screws and washers just to keep in place while I repaired the other ½ of the pump assembly.
Take the pulley and the body assembly up to the work bench.
Use a small screwdriver or snap ring pliers and remove the large snap ring (16) that is visible between the pulley (23) and the pulley end of the body (3). It is about 1” to 1.375” dia. Don’t remove the smaller ½” snap ring (11) on the pulley end.

Now on the impeller end:
Knock the Woodruff key off the shaft. Mine was tough. Used a hammer and round bar.
Remove the small snap ring (11) on the impeller end of the shaft.
Remove a large thin washer (12) from shaft. It’s about 1” dia..
Next I removed the old rubber washer and then the seat (13). The new seat has the washer pressed in and it fit tight.
Now I pulled the spring center of the seal (14) out, it came out easily and left behind the metal base.
Cleaned up the corrosion between the seal base (14) and the body (3)
Went to my buddy’s shop and used his shop press.
Supported the body and pressed the shaft and bearings out of the body in the direction of the pulley end
Clean up the gunk on the bearings. My bearings were fine plus the water is warming up for ski time.
With shaft/bearings out, I used a hammer and socket on an extension to beat the old seal out of the body from the pulley end towards the impeller end.
More clean up with small brass brush.
Place new Seal in place and use press with a very large socket to press seal into the body.
Pretty quick and easy from here on - just follow the assembly instructions from Sherwood site at the above link. I did not follow exactly. I put it back in the order I took apart and had to use my fingers to depress the spring center of the seal down while my friend could properly install the snap ring (11) .

The rubber side of the seat faces the impeller.
Remember to put the large snap ring (16) between the pulley and body.

[JayG80]

I learned something that the more experienced mechanics know about snap rings. It is best to open the up just enough to get them above the groove on the shaft. Then slide them off the end of shaft instead of trying to open them wide enough to slip off the side of the shaft. You might bend snap ring (11).

Also it is easier to put the larger snap ring (16) on the shaft before you press the bearings back into the body. I didn't, but it might be easier to get it positioned on the shaft during reassembly. Once the shaft is pressed back in place, you can set the loose snap ring into the proper spot.

[JayG80]

RWP bearings looked fine and I did not want to make a trip to auto parts store during the time I was at a friend's shop. I plan on helping a buddy with his rebuild and just found there is a minor rebuild kit online that includes seat, seal, c-rings, bearings and impeller for under $100. Sherwood shows it on their website as Minor rebuild kit 23979.

Looking at the PCM price list, there is a kit listed. RA057017 KIT, MINOR REPAIR (G21/G22) $124.09. Not certain what is in it.

[Bob Klauber]

heres how to disassemble a volvo penta sherwood raw water pump. 12328

do not try to remove the pulley.. its too weak for a puller, it will bend

remove impeller half and dissemble bearing block like this.

get a 20 ton 3 jaw puller, attach it with screw on center shaft rear.. not on the pulley side, on the impeller side, jaws on cast iron block.
small internal snap rings will break without damaging shaft when enough force is applied which is a lot, a SMALLER PULLER WILL BREAK
now you will be left with the shaft with the pulley still on it... remove broken snap ring pieces in the grooves
to remove 2 bearings.. remove large snap ring that is against the bearing then mount block in vise with bearings lower.
the 2 bearings have a spacer between them, it has a smaller outside diameter then the bearing outers so slide it off center and p;lace a rod against it and drive out the outer bearing.

now drive out the inner bearing with a socket as a driver.

go to the sherwood site to get the pdf showing parts diagram

I could not find this info online so mazeltov

[Merbesfield]

I just posted a thread about this and figured I would add my question to this one. I rebuilt mine but didn’t do the bearings. Should have bc they squeal bad. I am just going to replace the entire pump now. Has anyone used the aftermarket pumps vs the expensive Sherwood brand. Furthermore aftermarket part is from China. Let me know if anyone has experience.